一道英语选择题—————，they drew a conclusion.
A.The experiment making
B.The experiment did
C.The experiment having been done
D.The experiment made我认为答案C或D都对，但所给的参考答案是C。请专家们给与解释！
理论上确实CD都可以选 但做实验 多用 do an experiment 所以 D不够地道 C考察的是带主语的-ed分词分句 -ed做谓语的动词分句结构一共有三种 1.分句有主语和从属连词 2.分词从有属连词 3.分句有主语 eg：the job finished, we went home straight away.
这里的-ed可视作省略了 being 或 having been eg: my work(my work having been) done, i went to bed这就是所谓的“独立结构” （出自《新编英语语法教程》高等英语本科生教材）...
